This disclosure relates generally to fluid pumps, and more specifically to gear pumps for pressurizing a fluid.
Though gear pumps are considered highly reliable, in some aircraft engine applications, incorrectly or inconsistently pressurized fuel or oil can seriously affect engine system performance and reduce component life. For example, fuel exiting a gear pump with high pressure ripple can cause cycling and hunting on the fuel metering valve, and if severe enough, pressure pulsation and cavitation can cause damage to the pump, piping or the engine itself.
Rotary and reciprocating fluid pumps, depending on their design, can induce pressure waves, pulses, cavitation, and/or erosion damage both upstream and downstream of the pump. Fuel pump pressure ripple can be caused by the frequency of rotating device like a gear pump. The gear pump teeth provide cyclic flow with internal gear pockets rotating from the inlet port toward the discharge port. The continuous output of each of these pocket flow cycles produces what appears to be sequence flow output with an amplitude and frequency.